A general issue with bagless vacuum cleaners is loss of suction force, which results in impaired cleaning performance. Bagless vacuum cleaners normally comprise a filter unit for filtering the airflow before/upon exit of the dust bin or dust separator. After some time of operation of the vacuum cleaner, the filter unit gets covered with dust, which increases the airflow resistance through the filter unit, whereby the airflow is reduced, which in turn reduces the suction force of the vacuum cleaner. In order to reduce the risk of low performance of bagless vacuum cleaners due to poor suction force, the filter unit needs to be cleaned regularly.
Various solutions exist for achieving cleaning of filter units for bagless vacuum cleaners. Most commonly, the filter unit must be removed from the vacuum cleaner and be manually cleaned with water. Such manual cleaning action may be cumbersome for the user and when it is finished, the filter unit must be dried in open air for about 24 hours, during which period the vacuum cleaner cannot be used.
US 20080264007 A1 shows a motor driven filter cleaning mechanism, which may be operated while the filter unit is positioned in the vacuum cleaner.
However, the motor driven filter cleaning mechanism must be switched on by the user, which implies a risk that it gets forgotten and therefore gets done too seldom resulting in an impaired suction force of the vacuum cleaner.